X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/a3f9fd472c566d8351de941b066d8f225437d39d..797980252c46782a2b6afdc729088af5acff79bf:/src/xbt/context.c diff --git a/src/xbt/context.c b/src/xbt/context.c index 859ebd0421..136411cf09 100644 --- a/src/xbt/context.c +++ b/src/xbt/context.c @@ -24,217 +24,52 @@ static xbt_context_t current_context = NULL; static xbt_context_t init_context = NULL; static xbt_swag_t context_to_destroy = NULL; static xbt_swag_t context_living = NULL; -#ifdef CONTEXT_THREADS -static xbt_os_mutex_t creation_mutex; -static xbt_os_cond_t creation_cond; -#endif -static void __context_exit(xbt_context_t context, int value); -static void __xbt_context_yield(xbt_context_t context) -{ - xbt_assert0(current_context, "You have to call context_init() first."); - DEBUG2 - ("--------- current_context (%p) is yielding to context(%p) ---------", - current_context, context); -#ifdef CONTEXT_THREADS - if (context) { - xbt_context_t self = current_context; - DEBUG2("[%p] **** Locking ctx %p ****", self, context); - xbt_os_mutex_lock(context->mutex); - DEBUG1("[%p] **** Updating current_context ****", self); - current_context = context; - DEBUG1("[%p] **** Releasing the prisonner ****", self); - xbt_os_cond_signal(context->cond); - DEBUG3("[%p] **** Going to jail on individual %p/%p ****", self, - context->cond, context->mutex); - xbt_os_cond_wait(context->cond, context->mutex); - DEBUG2("[%p] **** Unlocking individual %p ****", self, context->mutex); - xbt_os_mutex_unlock(context->mutex); - DEBUG1("[%p] **** Updating current_context ****", self); - current_context = self; - } -#else /* use SUSv2 contexts */ - VOIRP(current_context); - if (current_context) - VOIRP(current_context->save); - - VOIRP(context); - - if (context) - VOIRP(context->save); - - if (context) { - - int return_value = 0; - - if (context->save == NULL) { - - DEBUG1("[%p] **** Yielding to somebody else ****", current_context); - DEBUG2("Saving current_context value (%p) to context(%p)->save", - current_context, context); - context->save = current_context; - DEBUG1("current_context becomes context(%p) ", context); - current_context = context; - DEBUG1 - ("Current position memorized (context->save). Jumping to context (%p)", - context); - return_value = swapcontext(&(context->save->uc), &(context->uc)); - xbt_assert0((return_value == 0), "Context swapping failure"); - DEBUG1("I am (%p). Coming back\n", context); - } else { - xbt_context_t old_context = context->save; - DEBUG1("[%p] **** Back ! ****", context); - DEBUG2("Setting current_context (%p) to context(%p)->save", - current_context, context); - current_context = context->save; - DEBUG1("Setting context(%p)->save to NULL", context); - context->save = NULL; - DEBUG2("Current position memorized (%p). Jumping to context (%p)", - context, old_context); - return_value = swapcontext(&(context->uc), &(old_context->uc)); - xbt_assert0((return_value == 0), "Context swapping failure"); - DEBUG1("I am (%p). Coming back\n", context); - - } - } -#endif - if (current_context->iwannadie) - __context_exit(current_context, 1); - - return; -} - -static void xbt_context_free(xbt_context_t context) +/********************/ +/* Module init/exit */ +/********************/ +#ifndef CONTEXT_THREADS +/* callback: context fetching (used only with ucontext, os_thread deal with it + for us otherwise) */ +static ex_ctx_t *_context_ex_ctx(void) { - if (!context) - return; - DEBUG1("Freeing %p", context); - free(context->name); -#ifdef CONTEXT_THREADS - /*DEBUG1("\t joining %p",(void *)context->thread->t); */ - DEBUG1("\t joining %p", (void *) context->thread); - - xbt_os_thread_join(context->thread, NULL); - - DEBUG1("\t mutex_destroy %p", (void *) context->mutex); - xbt_os_mutex_destroy(context->mutex); - DEBUG1("\t cond_destroy %p", (void *) context->cond); - xbt_os_cond_destroy(context->cond); - - context->thread = NULL; - context->mutex = NULL; - context->cond = NULL; -#else - if (context->exception) - free(context->exception); -#endif - - free(context); - return; + return current_context->exception; } -static void __context_exit(xbt_context_t context, int value) +/* callback: termination */ +static void _context_ex_terminate(xbt_ex_t * e) { - int i; - - DEBUG1("--------- %p is exiting ---------", context); - - DEBUG0("Calling cleanup functions"); - if (context->cleanup_func) { - DEBUG0("Calling cleanup function"); - context->cleanup_func(context->cleanup_arg); - } - - DEBUG0("Freeing arguments"); - for (i = 0; i < context->argc; i++) - if (context->argv[i]) - free(context->argv[i]); - - if (context->argv) - free(context->argv); - - DEBUG0("Putting context in the to_destroy set"); - xbt_swag_remove(context, context_living); - xbt_swag_insert(context, context_to_destroy); - DEBUG0("Context put in the to_destroy set"); - - DEBUG0("Yielding"); + xbt_ex_display(e); -#ifdef CONTEXT_THREADS - DEBUG2("[%p] **** Locking %p ****", context, context->mutex); - xbt_os_mutex_lock(context->mutex); -/* DEBUG1("[%p] **** Updating current_context ****"); */ -/* current_context = context; */ - DEBUG1("[%p] **** Releasing the prisonner ****", context); - xbt_os_cond_signal(context->cond); - DEBUG2("[%p] **** Unlocking individual %p ****", context, - context->mutex); - xbt_os_mutex_unlock(context->mutex); - DEBUG1("[%p] **** Exiting ****", context); - xbt_os_thread_exit(NULL); // We should provide return value in case other wants it -#else - __xbt_context_yield(context); -#endif - xbt_assert0(0, "You can't be here!"); + abort(); + /* FIXME: there should be a configuration variable to + choose to kill everyone or only this one */ } - -static void *__context_wrapper(void *c) -{ - xbt_context_t context = current_context; - -#ifdef CONTEXT_THREADS - context = (xbt_context_t) c; - context->thread = xbt_os_thread_self(); - - DEBUG3("**[ctx:%p;self:%p]** Lock creation_mutex %p ****", context, - (void *) xbt_os_thread_self(), creation_mutex); - xbt_os_mutex_lock(creation_mutex); - xbt_os_mutex_lock(context->mutex); - - DEBUG4 - ("**[ctx:%p;self:%p]** Releasing the creator (creation_cond %p,%p) ****", - context, (void *) xbt_os_thread_self(), creation_cond, - creation_mutex); - xbt_os_cond_signal(creation_cond); - xbt_os_mutex_unlock(creation_mutex); - - DEBUG4("**[ctx:%p;self:%p]** Going to Jail on lock %p and cond %p ****", - context, (void *) xbt_os_thread_self(), context->mutex, - context->cond); - xbt_os_cond_wait(context->cond, context->mutex); - - DEBUG3("**[ctx:%p;self:%p]** Unlocking individual %p ****", - context, (void *) xbt_os_thread_self(), context->mutex); - xbt_os_mutex_unlock(context->mutex); - #endif - if (context->startup_func) - context->startup_func(context->startup_arg); +#ifdef CONTEXT_THREADS - DEBUG0("Calling the main function"); +static void +schedule(xbt_context_t c); - __context_exit(context, (context->code) (context->argc, context->argv)); - return NULL; -} +static void +yield(xbt_context_t c); -#ifndef CONTEXT_THREADS -/* callback: context fetching (used only with ucontext, os_thread deal with it for us otherwise) */ -static ex_ctx_t *_context_ex_ctx(void) { - return current_context->exception; +static void +schedule(xbt_context_t c) +{ + xbt_os_sem_release(c->begin); + xbt_os_sem_acquire(c->end); } -/* callback: termination */ -static void _context_ex_terminate(xbt_ex_t * e) { - xbt_ex_display(e); - - abort(); - /* FIXME: there should be a configuration variable to - choose to kill everyone or only this one */ +static void yield(xbt_context_t c) +{ + xbt_os_sem_release(c->end); + xbt_os_sem_acquire(c->begin); } -#endif +#endif /** \name Functions * \ingroup XBT_context @@ -249,17 +84,13 @@ void xbt_context_init(void) if (!current_context) { current_context = init_context = xbt_new0(s_xbt_context_t, 1); DEBUG1("Init Context (%p)", init_context); - - init_context->iwannadie = 0; /* useless but makes valgrind happy */ + init_context->iwannadie = 0; /* useless but makes valgrind happy */ context_to_destroy = - xbt_swag_new(xbt_swag_offset(*current_context, hookup)); - context_living = - xbt_swag_new(xbt_swag_offset(*current_context, hookup)); + xbt_swag_new(xbt_swag_offset(*current_context, hookup)); + context_living = xbt_swag_new(xbt_swag_offset(*current_context, hookup)); xbt_swag_insert(init_context, context_living); -#ifdef CONTEXT_THREADS - creation_mutex = xbt_os_mutex_init(); - creation_cond = xbt_os_cond_init(); -#else + + #ifndef CONTEXT_THREADS init_context->exception = xbt_new(ex_ctx_t, 1); XBT_CTX_INITIALIZE(init_context->exception); __xbt_ex_ctx = _context_ex_ctx; @@ -268,55 +99,39 @@ void xbt_context_init(void) } } -/** Garbage collection - * - * Should be called some time to time to free the memory allocated for contexts - * that have finished executing their main functions. +/** + * This function kill all existing context and free all the memory + * that has been allocated in this module. */ -void xbt_context_empty_trash(void) +void xbt_context_exit(void) { xbt_context_t context = NULL; - DEBUG1("Emptying trashbin (%d contexts to free)", - xbt_swag_size(context_to_destroy)); - while ((context = xbt_swag_extract(context_to_destroy))) - xbt_context_free(context); -} -/** - * \param context the context to start - * - * Calling this function prepares \a context to be run. It will - however run effectively only when calling #xbt_context_schedule - */ -void xbt_context_start(xbt_context_t context) -{ -#ifdef CONTEXT_THREADS - /* Launch the thread */ - - DEBUG3("**[ctx:%p;self:%p]** Locking creation_mutex %p ****", context, - xbt_os_thread_self(), creation_mutex); - xbt_os_mutex_lock(creation_mutex); - - DEBUG2("**[ctx:%p;self:%p]** Thread create ****", context, - xbt_os_thread_self()); - context->thread = xbt_os_thread_create(context->name,__context_wrapper, context); - DEBUG3("**[ctx:%p;self:%p]** Thread created : %p ****", context, - xbt_os_thread_self(), context->thread); - - DEBUG4 - ("**[ctx:%p;self:%p]** Going to jail on creation_cond/mutex (%p,%p) ****", - context, xbt_os_thread_self(), creation_cond, creation_mutex); - xbt_os_cond_wait(creation_cond, creation_mutex); - DEBUG3("**[ctx:%p;self:%p]** Unlocking creation %p ****", context, - xbt_os_thread_self(), creation_mutex); - xbt_os_mutex_unlock(creation_mutex); -#else - makecontext(&(context->uc), (void (*)(void)) __context_wrapper, 1, - context); + xbt_context_empty_trash(); + + while ((context = xbt_swag_extract(context_living))) { + if (context != init_context) { + xbt_context_kill(context); + } + } + +#ifndef CONTEXT_THREADS + free(init_context->exception); #endif - return; + + free(init_context); + init_context = current_context = NULL; + + xbt_context_empty_trash(); + xbt_swag_free(context_to_destroy); + xbt_swag_free(context_living); + } + +/*******************************/ +/* Object creation/destruction */ +/*******************************/ /** * \param code a main function * \param startup_func a function to call when running the context for @@ -328,11 +143,14 @@ void xbt_context_start(xbt_context_t context) * \param argc first argument of function \a code * \param argv seconde argument of function \a code */ -xbt_context_t xbt_context_new(const char *name,xbt_main_func_t code, - void_f_pvoid_t startup_func, - void *startup_arg, - void_f_pvoid_t cleanup_func, - void *cleanup_arg, int argc, char *argv[]) +xbt_context_t +xbt_context_new(const char *name, + xbt_main_func_t code, + void_f_pvoid_t startup_func, + void *startup_arg, + void_f_pvoid_t cleanup_func, + void *cleanup_arg, int argc, char *argv[] + ) { xbt_context_t res = NULL; @@ -340,27 +158,31 @@ xbt_context_t xbt_context_new(const char *name,xbt_main_func_t code, res->code = code; res->name = xbt_strdup(name); + #ifdef CONTEXT_THREADS - res->mutex = xbt_os_mutex_init(); - res->cond = xbt_os_cond_init(); + /* + * initialize the semaphores used to schedule/yield + * the process associated to the newly created context + */ + res->begin = xbt_os_sem_init(0); + res->end = xbt_os_sem_init(0); #else xbt_assert2(getcontext(&(res->uc)) == 0, - "Error in context saving: %d (%s)", errno, strerror(errno)); + "Error in context saving: %d (%s)", errno, strerror(errno)); res->uc.uc_link = NULL; /* res->uc.uc_link = &(current_context->uc); */ /* WARNING : when this context is over, the current_context (i.e. the father), is awaken... Theorically, the wrapper should prevent using this feature. */ res->uc.uc_stack.ss_sp = pth_skaddr_makecontext(res->stack, STACK_SIZE); - res->uc.uc_stack.ss_size = - pth_sksize_makecontext(res->stack, STACK_SIZE); - + res->uc.uc_stack.ss_size = pth_sksize_makecontext(res->stack, STACK_SIZE); + res->exception = xbt_new(ex_ctx_t, 1); XBT_CTX_INITIALIZE(res->exception); -#endif /* CONTEXT_THREADS or not */ +#endif /* CONTEXT_THREADS or not */ - res->iwannadie = 0; /* useless but makes valgrind happy */ + res->iwannadie = 0; /* useless but makes valgrind happy */ res->argc = argc; res->argv = argv; @@ -374,10 +196,261 @@ xbt_context_t xbt_context_new(const char *name,xbt_main_func_t code, return res; } +/* Scenario for the end of a context: + * + * CASE 1: death after end of function + * __context_wrapper, called by os thread, calls xbt_context_stop after user code stops + * xbt_context_stop calls user cleanup_func if any (in context settings), + * add current to trashbin + * yields back to maestro (destroy os thread on need) + * From time to time, maestro calls xbt_context_empty_trash, + * which maps xbt_context_free on the content + * xbt_context_free frees some more memory, + * joins os thread + * + * CASE 2: brutal death + * xbt_context_kill (from any context) + * set context->wannadie to 1 + * yields to the context + * the context is awaken in the middle of __yield. + * At the end of it, it checks that wannadie == 1, and call xbt_context_stop + * (same than first case afterward) + */ + + +/* Argument must be stopped first -- runs in maestro context */ +static void xbt_context_free(xbt_context_t context) +{ + int i; + + if (!context) + return; + + DEBUG1("Freeing %p", context); + free(context->name); + + DEBUG0("Freeing arguments"); + + for (i = 0; i < context->argc; i++) + if (context->argv[i]) + free(context->argv[i]); + + if (context->argv) + free(context->argv); + +#ifdef CONTEXT_THREADS + DEBUG1("\t joining %p", (void *) context->thread); + + xbt_os_thread_join(context->thread, NULL); + + /* destroy the semaphore used to schedule/unshedule the process */ + xbt_os_sem_destroy(context->begin); + xbt_os_sem_destroy(context->end); + + context->thread = NULL; + context->begin = NULL; + context->end = NULL; +#else + if (context->exception) + free(context->exception); +#endif + + free(context); +} + +/************************/ +/* Start/stop a context */ +/************************/ +static void xbt_context_stop(int retvalue); +static void __xbt_context_yield(xbt_context_t context); + +static void *__context_wrapper(void *c) +{ + xbt_context_t context = current_context; + +#ifdef CONTEXT_THREADS + context = (xbt_context_t) c; + /*context->thread = xbt_os_thread_self();*/ + + /* signal its starting to the maestro and wait to start its job*/ + yield(context); + +#endif + + if (context->startup_func) + context->startup_func(context->startup_arg); + + DEBUG0("Calling the main function"); + + xbt_context_stop((context->code) (context->argc, context->argv)); + return NULL; +} +/** + * \param context the context to start + * + * Calling this function prepares \a context to be run. It will + however run effectively only when calling #xbt_context_schedule + */ +void xbt_context_start(xbt_context_t context) +{ +#ifdef CONTEXT_THREADS + /* create the process and start it */ + context->thread = xbt_os_thread_create(context->name,__context_wrapper, context); + + /* wait the starting of the newly created process */ + xbt_os_sem_acquire(context->end); +#else + makecontext(&(context->uc), (void (*)(void)) __context_wrapper, 1, context); +#endif +} + +/* Stops current context: calls user's cleanup function, kills os thread, and yields back to maestro */ +static void xbt_context_stop(int retvalue) +{ + DEBUG1("--------- %p is exiting ---------", current_context); + + if (current_context->cleanup_func) { + DEBUG0("Calling cleanup function"); + current_context->cleanup_func(current_context->cleanup_arg); + } + + DEBUG0("Putting context in the to_destroy set"); + xbt_swag_remove(current_context, context_living); + xbt_swag_insert(current_context, context_to_destroy); + + DEBUG0("Yielding"); + +#ifdef CONTEXT_THREADS + /* signal to the maestro that it has finished */ + xbt_os_sem_release(current_context->end); + /* exit*/ + xbt_os_thread_exit(NULL); /* We should provide return value in case other wants it */ +#else + __xbt_context_yield(current_context); +#endif + THROW_IMPOSSIBLE; +} + + + +/** Garbage collection + * + * Should be called some time to time to free the memory allocated for contexts + * that have finished executing their main functions. + */ +void xbt_context_empty_trash(void) +{ + xbt_context_t context = NULL; + + DEBUG1("Emptying trashbin (%d contexts to free)", + xbt_swag_size(context_to_destroy)); + + while ((context = xbt_swag_extract(context_to_destroy))) + xbt_context_free(context); +} + +/*********************/ +/* context switching */ +/*********************/ + +static void __xbt_context_yield(xbt_context_t context) +{ + xbt_assert0(current_context, "You have to call context_init() first."); + xbt_assert0(context, "Invalid argument"); + + if (current_context == context) { + DEBUG1 + ("--------- current_context (%p) is yielding back to maestro ---------", + context); + } else { + DEBUG2 + ("--------- current_context (%p) is yielding to context(%p) ---------", + current_context, context); + } + +#ifdef CONTEXT_THREADS + + if(current_context != init_context && !context->iwannadie) + {/* it's a process and it doesn't wants to die (xbt_context_yield()) */ + + /* save the current context */ + xbt_context_t self = current_context; + + /* update the current context to this context */ + current_context = context; + + /* yield itself */ + yield(context); + + /* restore the current context to the previously saved context */ + current_context = self; + } + else + { /* maestro wants to schedule a process or a process wants to die (xbt_context_schedule() or xbt_context_kill())*/ + + /* save the current context */ + xbt_context_t self = current_context; + + /* update the current context */ + current_context = context; + + /* schedule the process associated with this context */ + schedule(context); + + /* restore the current context to the previously saved context */ + current_context = self; + } + +#else /* use SUSv2 contexts */ + VOIRP(current_context); + VOIRP(current_context->save); + + VOIRP(context); + VOIRP(context->save); + + int return_value = 0; + + if (context->save == NULL) { + DEBUG1("[%p] **** Yielding to somebody else ****", current_context); + DEBUG2("Saving current_context value (%p) to context(%p)->save", + current_context, context); + context->save = current_context; + DEBUG1("current_context becomes context(%p) ", context); + current_context = context; + DEBUG1 + ("Current position memorized (context->save). Jumping to context (%p)", + context); + return_value = swapcontext(&(context->save->uc), &(context->uc)); + xbt_assert0((return_value == 0), "Context swapping failure"); + DEBUG1("I am (%p). Coming back\n", context); + } else { + xbt_context_t old_context = context->save; + + DEBUG1("[%p] **** Back ! ****", context); + DEBUG2("Setting current_context (%p) to context(%p)->save", + current_context, context); + current_context = context->save; + DEBUG1("Setting context(%p)->save to NULL", context); + context->save = NULL; + DEBUG2("Current position memorized (%p). Jumping to context (%p)", + context, old_context); + return_value = swapcontext(&(context->uc), &(old_context->uc)); + xbt_assert0((return_value == 0), "Context swapping failure"); + DEBUG1("I am (%p). Coming back\n", context); + } +#endif + + if (current_context->iwannadie) + xbt_context_stop(1); +} + /** * Calling this function makes the current context yield. The context * that scheduled it returns from xbt_context_schedule as if nothing * had happened. + * + * Only the processes can call this function, giving back the control + * to the maestro */ void xbt_context_yield(void) { @@ -390,43 +463,17 @@ void xbt_context_yield(void) * Calling this function blocks the current context and schedule \a context. * When \a context will call xbt_context_yield, it will return * to this function as if nothing had happened. + * + * Only the maestro can call this function to run a given process. */ void xbt_context_schedule(xbt_context_t context) { DEBUG1("Scheduling %p", context); xbt_assert0((current_context == init_context), - "You are not supposed to run this function here!"); + "You are not supposed to run this function here!"); __xbt_context_yield(context); } -/** - * This function kill all existing context and free all the memory - * that has been allocated in this module. - */ -void xbt_context_exit(void) -{ - xbt_context_t context = NULL; - - xbt_context_empty_trash(); - while ((context = xbt_swag_extract(context_living))) { - if (context != init_context) { - xbt_context_kill(context); - } - } -#ifdef CONTEXT_THREADS - xbt_os_mutex_destroy(creation_mutex); - xbt_os_cond_destroy(creation_cond); -#else - free(init_context->exception); -#endif - free(init_context); - init_context = current_context = NULL; - - xbt_context_empty_trash(); - xbt_swag_free(context_to_destroy); - xbt_swag_free(context_living); - -} /** * \param context poor victim @@ -438,44 +485,16 @@ void xbt_context_kill(xbt_context_t context) DEBUG1("Killing %p", context); context->iwannadie = 1; + DEBUG1("Scheduling %p", context); __xbt_context_yield(context); DEBUG1("End of Scheduling %p", context); - - return; -} - -/* @} */ - -/* Stub of the stuff to interact with JAVA threads; not used in native lib */ -void xbt_context_set_jprocess(xbt_context_t context, void *jp) -{ -} -void *xbt_context_get_jprocess(xbt_context_t context) -{ - return NULL; -} - -void xbt_context_set_jmutex(xbt_context_t context, void *jm) -{ -} -void *xbt_context_get_jmutex(xbt_context_t context) -{ - return NULL; } -void xbt_context_set_jcond(xbt_context_t context, void *jc) -{ -} -void *xbt_context_get_jcond(xbt_context_t context) -{ - return NULL; -} +/* Java cruft I'm gonna kill in the next cleanup round */ +void xbt_context_set_jprocess(xbt_context_t context, void *jp){} +void* xbt_context_get_jprocess(xbt_context_t context){return NULL;} +void xbt_context_set_jenv(xbt_context_t context,void* je){} +void* xbt_context_get_jenv(xbt_context_t context){return NULL;} -void xbt_context_set_jenv(xbt_context_t context, void *je) -{ -} -void *xbt_context_get_jenv(xbt_context_t context) -{ - return NULL; -} +/* @} */